Odometer keeps running | FerrariChat

Odometer keeps running

Discussion in 'Boxers/TR/M' started by spaceship, Sep 16, 2018.

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  1. spaceship

    spaceship Karting

    Feb 25, 2016
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    S. Chan
    #1 spaceship, Sep 16, 2018
    On my 91 Japanese version Testarossa, which has a separated odometer/trip meter in the lower center console as the European version. The odometer is running all the time when the car is switched on (even the engine is off), at the speed of around 100 meters per second. The odometer starts to run after around 30 seconds of power on. The speedometer is working correctly. Any idea what's going on?

    There is a square 9 pin plug behind the odometer, anyone has wiring diagram for the connector that can share?

    Thank you very much.
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    Steve Magnusson
    #2 Steve Magnusson, Sep 17, 2018
    The speedometer and odometer share the same signal so would have to suspect the odometer itself having a problem if the speedometer is working correctly.

    You can download a copy of the euro TR 459/86 wiring diagram here:

    https://www.dropbox.com/s/ox8kxpyzlsid9jn/Wiring%20Diagrams%20TR%20459_86%20from%20Ben.pdf?dl=0

    It also has the center console odometer configuration (Fig 7), and I would guess that the wiring connection scheme is the same. My quick reading of the tea leaves from Fig 4 and Fig 7 of 459/86:

    RV (red-green) = always +12V
    N (black) = ground
    VB (green-white) = goes +12V with key "on"
    RN (red-black) = signal from the speed sensor on the gearbox (would be a variable square wave when the key is "on" and the rear wheels are turning)
    G (yellow) = a positive voltage from the illumination rheostat (so goes 0-12V when turning the rheostat knob when the lights are "on")
    SG (pink-yellow) = +12V when the headlight stalk knob is rotated "on"
    V (green) = +12V supplied to the speed sensor on the gearbox with key "on"

    Good Hunting!
     
  3. spaceship

    spaceship Karting

    Feb 25, 2016
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    #3 spaceship, Sep 17, 2018
    Great, thank you so much, Steve!
    I have all the color wires as described, and one more - a blue one. I think it's good enough to start some testings.
     
  4. ozziindaus

    ozziindaus F1 Veteran
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    #4 ozziindaus, Sep 18, 2018
    Now time for some roll back :rolleyes:
     
  5. spaceship

    spaceship Karting

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    #5 spaceship, Sep 28, 2018
    The circuit board was inspect by a friend with electronic knowledge, he suspected the IC 92967 in the picture might be bad. However, we couldn't find any information by Google, no datasheet, no replacement. Any idea if there is any replacement for this? Thanks.
    Image Unavailable, Please Login
     
  6. RedNeck

    RedNeck F1 World Champ
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    #6 RedNeck, Sep 28, 2018
    I used to have to source electronic components, don't recognize the marking. Maybe I can send the pic to some of my old co-workers to see if they do.
     
  7. spaceship

    spaceship Karting

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    #7 spaceship, Sep 29, 2018
    Thank you RedNeck!
     

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